Abstract: To survey a subterranean structure, for acquiring an electromagnetic (EM) measurement signal across EM receivers having a target axial spacing, a group of more than two EM receivers in an interval defined by the target axial spacing along a sensor cable is provided. The spacing between successive ones of at least some EM receivers in the group is less than the target axial spacing. EM measurements are acquired using the EM receivers in the group.
Abstract: Adaptive filtering method to remove ground roll from seismic data. In an M channel adaptive filter, weights Wi are set using an adaptive algorithm based on seeking the minimum in the partial differential of cost function J. The cost function includes an expansion of the primary trace d into d=dg+?d (where: dg is ground roll contribution and ?d=dsig+dran, where dsig is the reflected signal component and dran is a random noise component) and a corresponding expansion of the reference x into x=xg+?x (where xg is ground roll contribution and ?x=xsig+xran; where xsig is a reflected signal component and xran is a random noise component). The delta components are included in the denominator of cost function J to provide an optimal solution of the filter coefficients biased by the reflection signal and random noise is removed.
Abstract: A technique includes obtaining multi-component seismic data acquired by two or more seismic sensors while in tow. The multi-component seismic data is indicative of a pressure wavefield and particle motion. The technique includes based on the data, determining at least one high order (i.e., second order or higher) spatial derivative of the pressure wavefield.
Type:
Grant
Filed:
May 25, 2008
Date of Patent:
February 24, 2015
Assignee:
WesternGeco L.L.C.
Inventors:
Massimiliano Vassallo, Johan Olof Anders Robertsson, Dirk-Jan Van Manen
Abstract: Methods for efficiently acquiring full-azimuth towed streamer survey data are described. The methods use multiple vessels to perform coil shooting.
Abstract: Implementations of various technologies for a method for processing seismic data. In one implementation, the method may include receiving a record of seismic data. The record of seismic data may have a plurality of attributes. A first seismic data process may be performed on the record of seismic data. The first seismic data process may generate a plurality of datasets. A selection of a portion of the plurality of attributes for ranking the datasets may be received. A quality score may be determined for each attribute of the portion of the plurality of attributes for each dataset. A ranking may be determined for each dataset based on the quality score.
Type:
Grant
Filed:
October 7, 2008
Date of Patent:
February 10, 2015
Assignee:
WesternGeco L.L.C.
Inventors:
Horacio R. Bouzas, Ian Scott, Gerard Kavanagh
Abstract: A method for processing seismic data. The method includes receiving the seismic data acquired by at least two receivers that are disposed at different depths. The method may then time-align the seismic data, collect a portion of the time-aligned seismic data into a gather and sum the collected time-aligned seismic data in the gather. After summing the collected time-aligned seismic data in the gather, the method may widen a spectrum of the summed seismic data and generate an image of subsurface formations in the earth based on the widened spectrum.
Abstract: A technique includes generating seismic sweep sequences. Each of the seismic sweep sequences has an associated sweep rate. The technique includes varying the sweep rates to reduce harmonic distortion present in a composite seismic measurement produced in response to the sweep sequences.
Abstract: A seismic streamer system for acquiring seismic data includes a plurality of first cable sections each employing a first sensor configuration therein, and at least one second cable section operatively connected to one or more of the first cable sections and employing a second sensor configuration therein. In various embodiments of the streamer system, one or more of the second cable sections are sparsely integrated into a streamer, a streamer array and/or a seismic spread. The first sensor configuration may, e.g., include a conventional hydrophone distribution, and the second sensor configuration may, e.g., include multicomponent sensors such as at least one of a particle velocity sensor, a pressure gradient sensor, an accelerometer and a combination thereof. The present invention is useful for attenuating noise in the measured seismic data as well as deghosting the data.
Type:
Grant
Filed:
July 2, 2013
Date of Patent:
January 27, 2015
Assignee:
WesternGeco L.L.C.
Inventors:
Roshitashva Singh, Johan O. A. Robertsson, Ottar Kristiansen
Abstract: A method for managing a fracturing operation. In one implementation, the method may include positioning one or more sources and one or more receivers near a hydrocarbon reservoir; pumping a fracturing fluid into a well bore of the hydrocarbon reservoir; performing a survey with the sources and the receivers during the fracturing operation; comparing the baseline survey to the survey performed during the fracturing operation; analyzing one or more differences between the baseline survey and the survey performed during the fracturing operation; and modifying the fracturing operation based on the differences.
Abstract: A method for evaluating a quality of a seismic inversion. The method includes performing a first match between seismic data and borehole seismic data at one or more borehole locations to generate an estimate of a wavelet in the seismic data. The method then performs a seismic inversion on the seismic data using the estimate of the wavelet to generate inverted seismic data. After performing the seismic inversion, the method converts the inverted seismic data into one or more reflectivity traces. The method then includes performing a second match between the one or more reflectivity traces and one or more traces in the seismic data and performing a third match between the one or more reflectivity traces and one or more traces in the borehole seismic data. After performing the second and third matches, the method determines the quality of the seismic inversion based on the first match, the second match, the third match or combinations thereof.
Abstract: A technique for providing short circuit protection in electrical systems used in hydrocarbon exploration and production and, more particularly, for such electrical systems comprising serially connected nodes, includes an apparatus and method. The apparatus, includes a power supply and a plurality of electrically serially connected application sensors downstream from the power supply. Each application sensor includes a sensing element; and a plurality of electronics associated with the sensing element. The electronics shut off upstream power to the downstream application sensors in the presence of a short circuit. The method includes serially supplying power to a downhole apparatus comprising a plurality of electrically serially connected downhole sensors; sensing, in series and upon receiving power from upstream, at each downhole sensor whether a downstream short circuit exists; and shutting off upstream power to the downstream downhole sensors in the presence of a short circuit.
Abstract: To estimate a far-field signature of a seismic source having plural source elements, seismic receivers are provided to receive signals from the seismic source elements of the seismic source. Seismic receivers are dynamically associated with different seismic source elements over time, and the far-field signature of the seismic source is computed according to the measurement data taken by the seismic receivers.
Abstract: Disclosed herein are implementations of various technologies for a method for seismic data processing. The method may receive seismic data for a region of interest. The seismic data may be acquired in a seismic survey. The method may determine an exclusion criterion. The exclusion criterion may provide rules for selecting shot points in the acquired seismic data. The method may determine sparse seismic data using statistical sampling based on the exclusion criterion and the acquired seismic data. The method may determine simulated seismic data based on the earth model and shot points corresponding to the sparse seismic data. The method may determine an objective function that represents a mismatch between the sparse seismic data and the simulated seismic data. The method may update the earth model using the objective function.
Type:
Application
Filed:
May 30, 2014
Publication date:
December 18, 2014
Applicant:
WESTERNGECO L.L.C.
Inventors:
KUN JIAO, RICHARD TIMOTHY COATES, WEI HUANG, ALAN SCHIEMENZ, DENES VIGH
Abstract: Rock physics guided migration is disclosed to enhance subsurface three-dimensional geologic formation evaluation. In one embodiment, a geologic interpretation is generated based on a seismic data volume. Sets of compaction and acoustic formation factor curves are generated, and these are combined into a set of velocity-relationship curves. A pore pressure is derived and used to establish a pore pressure state. A rock physics template is then generated utilizing the derived information. This rock physics template can be used to refine geologic formation evaluation with any suitable form of migration technique.
Abstract: A hydrocarbon application cable of reduced nylon with increased flexibility and useful life. The cable may be of a hose or solid configuration and particularly beneficial for use in marine operations. A power and data communicative core of the cable may be surrounded by a lightweight intermediate polymer layer of a given hardness which is ultimately then surrounded by an outer polymer jacket having a hardness that is greater than the given hardness. Thus, a lighter weight polymer is provided interior of the outer polymer jacket, which may be of nylon or other suitably hard material. As such, the overall weight and cost of the cable may be substantially reduced.
Type:
Grant
Filed:
March 24, 2009
Date of Patent:
December 16, 2014
Assignee:
WesternGeco L.L.C.
Inventors:
Joseph Varkey, Jushik Yun, Byong Jun Kim
Abstract: A technique includes a technique includes providing a plurality of acquisition components for performing a survey of a geologic region of interest, where the plurality of acquisition components comprising receivers and at least one source. The technique includes using at least one marine unmanned vehicle to position at least one of the receivers in the survey; and deploying at least at one of the acquisition components in a well or on land.
Type:
Application
Filed:
April 11, 2014
Publication date:
December 11, 2014
Applicant:
WESTERNGECO L.L.C.
Inventors:
EVERHARD JOHAN MUIJZERT, OLAV LIEN, KENNETH E. WELKER, SUDHIR PAI, HENRY MENKITI, NICOLAE MOLDOVEANU, IAIN COOPER
Abstract: An apparatus includes a streamer cable having one or more seismic devices disposed within a polymer body and about a core. The polymer body includes a channel defined therein for receiving one or more wires connecting the seismic devices. The wires include slack for withstanding the tensional forces experienced by the streamer cable during deployment and operation. Associated methods are also described.
Abstract: A method for determining a sail plan for a towed-array marine seismic survey includes: dividing a survey area into a regular grid of tiles; and identifying a subset of the tiles as nodes around which continuously curved sail lines are defined. The nodes define regular pattern further including: a first subpattern of nodes; and a second subpattern of nodes offset from the first subpattern. A method for conducting a towed array marine survey includes: traversing a plurality of continuously curved sail lines across a survey area, each sail line being relative to a node; and acquiring seismic data while traversing the continuously curved sail lines. The set of nodes defining a regular pattern further including: a first subpattern of nodes; and a second subpattern of nodes offset from the first subpattern.
Type:
Grant
Filed:
July 16, 2013
Date of Patent:
December 9, 2014
Assignee:
WesternGeco L.L.C.
Inventors:
David Ian Hill, Nicolae Moldoveanu, Steven Fealy
Abstract: A control system for use in a marine seismic survey is provided. The system may include one or more processors configured to receive a desired position for one or more seismic streamers during the marine seismic survey. The one or more processors may be further configured to determine a current position for the one or more seismic streamers and to adjust a position of a steering device on each streamer, based upon, at least in part, a comparison between the current position of the one or more seismic streamers and the desired position of the one or more seismic streamers.
Type:
Application
Filed:
May 28, 2014
Publication date:
December 4, 2014
Applicant:
WESTERNGECO L.L.C.
Inventors:
NICOLAS BARRAL, HALVOR S. GRØNAAS, ANTONIN BERTIN
Abstract: A technique includes receiving seismic data acquired in a seismic survey. The technique includes determining a geophysical trend of trace amplitudes indicated by the seismic data based on non-linear regression and performing quality control analysis on the seismic data based on the determined trend.